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Locai Labs

Software Engineer (Backend, AI Systems)

On site

London, United kingdom

Junior

Full Time

01-11-2025

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Skills

Python JavaScript TypeScript SQL NoSQL GraphQL Docker Problem-solving Research Architecture Databases Autonomy react node.js AWS cloud platforms JavaScript/TypeScript GCP Langchain Large Language Models Kafka

Job Specifications

About Locai Labs 

Locai Labs is The British Foundational AI Company, based in Paddington, London. 

We are dedicated to building world-class large language models at the forefront of cost, efficiency, and capability. 

Our mission is to advance cutting-edge AI from within the UK by combining deep technical innovation with engineering excellence, creating scalable models and intelligent systems that power next-generation applications for consumers and enterprises alike. 

Our work spans across: 

Foundational AI model development 
Bespoke agentic applications for enterprise and consumer domains 
APIs and developer tools that enable intelligent automation 

 

The Role 

We are seeking a Software Engineer (Backend, AI Systems) to design and build the backend systems, APIs, and tools that power Locai Labs’ AI models and agentic platforms. 

You will work on a diverse range of challenges, from model-serving APIs and data pipelines to infrastructure for intelligent agents and automation frameworks. 

This is a hands-on engineering role for someone who enjoys solving complex technical problems and shipping impactful products. 

You will collaborate closely with the CTO and engineering team to design, build, and scale production systems that integrate AI into real-world applications. 

 

Responsibilities 

Design and develop backend systems and APIs for AI-driven products and agent frameworks 
Integrate LLMs into scalable, production-ready systems 
Build internal tools and services to manage agents, workflows, and orchestration logic 
Collaborate with frontend, infrastructure, and research teams to deliver cohesive product experiences 
Contribute to system architecture, technical design, and engineering best practices 
Write clean, maintainable, and well-tested code 

 

Required Experience 

2–5 years of professional software engineering experience, ideally working on backend systems, APIs, or AI-related products 
Proficiency in Python and JavaScript/TypeScript (Node.js) 
Strong understanding of backend architectures, REST/GraphQL APIs, and data modelling 
Experience with containerisation (Docker) and cloud platforms (GCP, AWS, or similar) 
Familiarity with LLM or AI APIs
Exposure to agentic frameworks (LangChain, LlamaIndex, Semantic Kernel, etc.) 
Practical experience with databases (SQL / NoSQL) 
Strong foundation in software design principles and systems thinking 
Comfortable working in a fast-paced, early-stage start-up environment with ownership and autonomy 

 

Nice to Have 

Experience with vector databases or embedding pipelines 
Understanding of event-driven or real-time systems (Kafka, Pub/Sub, etc.) 
Knowledge of API authentication, access control, or multi-tenant architectures 
Familiarity with React or other front-end frameworks (for internal tools) 
Interest in applied AI research, model fine-tuning, or reasoning agents 

 

Environment and Culture 

You will join a small, highly technical team where your contributions directly shape the company’s technology and products. 

We value ownership, curiosity, and pragmatism; every engineer at Locai Labs helps define architecture, infrastructure, and product direction. 

You will work on-site at our Paddington HQ, collaborating closely with the CTO and engineering team in a transparent, fast-moving, and innovation-focused environment. 

 

Application Process 

Application Review – We evaluate your background and experience. 
Take-Home Technical Assessment – A short exercise to demonstrate your engineering approach. 
Technical Interview – Discussion of technical depth, design thinking, and problem-solving. 
On-Site Session at HQ – Collaboration exercises and technical discussions with the team. 
Offer – Formal offer and next steps. 

If this sounds like you, we would love to hear from you. 

Apply directly via the form below: 

https://forms.office.com/e/YQcaKRvdrN

(Strictly no agencies or recruiters. We are only accepting direct applications.) 

About the Company

At Locai Labs we build cutting-edge enterprise AI solutions that span industries — from retail and e-commerce to healthcare, telecoms, and financial services. Our technology powers intelligent, real-time interactions that boost performance, reduce friction, and unlock new ways of working. View our research at: locailabs.com/research Know more